Multiple lamp apparatus for interchanging liquid-cooled lamps



Oct. 2, 1951 E. c. WEISKOPF 2,569,876

MULTIPLE LAMP APPARATUS FOR INTERCHANGING LIQUID-COOLED LAMPS Filed March 14, 1947 4 Sheets-Sheet l ATTORNEY 1951 E. c. WEISKOPF' MULTIPLE LAMP APPARATUS FOR INTERCHANGING LIQUID-COOLED LAMPS 4 Sheets-Sheet :5

Filed March 14, 1947 INVENTOR EDWIN a WE/SKOPF d-q'ny ATTORNEY Oct. 2, 1951 E c WEISKOPF 1 2,569,876

MULTIPLE LAMP APPARATUS FOR INTERCHANGING LIQUID-COOLED LAMPS Filed March 14, 1947 4 Sheets-Sheet 4 1 NNNNNN OR EDWM/ C WEE/(01F ATTORN EY Patented Oct. 2, 1951 MULTIPLE LAMP APPARATUS FOR INTER- CHANGING LIQUID-COOLED LAMPS Edwin C. Weiskopf, New York, N. Y. Application March 14, 1947, Serial No. 734,585

14 Claims. 1

This invention relates to multiple lamp apparatus which is particularly well adapted for use in light projectors for micro projection apparatus but which can be used generally for various purposes as a light source.

Thejprimary object of this invention is the provision of amultiple lamp device constructed and arranged so that when one lamp becomes inoperative or defective another lamp may be quickly and easily brought into operation.

Another object of this invention is to provide a multiple lamp device having a plurality of lamps mounted in readiness for use and movable in relation to a light outlet so that when one of said lamps becomes defective or inoperative, another of said lamps may be quickly and easily brought into operation and positioned with respect to the light outlet, without requiring removal of the inoperative or defective lamp unless all of the lamps are burned out or otherwise become inoperative as a light source.

Another object of the invention is the provision of a multiple lamp device in which the lamps are provided with cooling means and in which such lamps are movable to and from operative positions.

A further object of the invention is generally to provide a multiple lamp device which is particularly well adapted to providean intense light for micro projection apparatus or for other purposes. r

The above and other objects, features and advantages of this invention will be fully understood from the following description considered in connection with the accompanying, illustrative drawings.

4 In the drawings: Fig. l is a sectional'view of a light projector embodying the present invention, showing the multiple'larnp device in elevation, parts of the projector being shown in elevation;

Fig. 2 is a view of the device as seen from the line 22 of Fig. 1;

- Fig. 3 is a sectional view, on a larger scale, on the line 3-3 of Fig. 1;

' Fig. 4 is a sectional view on a larger scale on the line 4-4 of Fig. 1;

Fig. 5 is a sectional view on the line 5-5 of Fig. 3;

Fig. 6 is an end view of the multiple lamp device as seen from the right of Fig. 2;

Fig. 7 is a sectional view on the line 1-1 in Fig. 3.

Referring now to the drawings in detail, the multiple lamp device l0 embodying the present invention is shown mounted in a lamp hous-.

lng i2 of a light projector. Said housing is provided with a light outlet I4 and a condensing lens l6 which is adjustable toward and away from the light outlet and from the operative lamp of the device it}. The lens holder 18 is carried by a bracket 2% which is fixed to and is movable with a rod 22, the latter being mounted for longitudinal movement in aligned guide bearings 24 and 23. Rod 22 may be adjusted in any suitable way, preferably by the mechanism shown and described in my application Serial Number 693,292, filed August 27, 1946, now Patent Number 2,477,396, dated July 27, 1949. The lamp housing I2 is also preferably of the construction shown in my said application.

The multiple lamp device It of the present invention comprises a plurality of lamps 28 which, as here shown are of the water-cooled, mercury-vapor, high voltage type. Each of said lamps is preferably of the type described in U. S. Letters Patent No. 2,094,694 and comprises a quartz capillary tube 30 (Fig. 3), containing spaced electrodes at their opposite ends, respectively, pools of mercury adjacent said electrodes, and a discharge gas such as argon. These lamps are 01 a known construction and therefore require no further description. Each lamp tube 3:: is disposed within a companion jacket-tube 32 through which a cooling medium, such as Water, flows for cooling the lamp in the operation thereof. Water-jacket tube 32 is provided with a constricted portion 34 which extends 1ongitudinally of capillary tube 3%] in the portion thereof from which the light is transmitted to the microscope of the micro projection apparatus, as described in my abovementioned prior application. The opposite ends of lamp tube 38 are provided with conductor terminals 36 which are in mechanical and electrical engagement with the companion conducting terminal members and supports 38 and 40 respectively. Terminal conductor members 38 and 40 are mounted in the members 42 and 44 of the movable-lamp holding means of the present invention. Member 42 is formed of insulation material and member 44 is formed of metal. Each terminal conductor member 38 is carried by a stem 46 which is slidable in a companion guide member 48 which is fixed in a metal tube 50 carried by holder member 42. A spring 52 is provided between guide member 48 and terminal conductor member 38 for biasing the latter into firm engagement with the lamp terminal 36. Guide member 48 has peripheral portions thereof spaced from the inner surface of the tube so as not to interfere with the passage of water through said tube, but it will be noted that stem 46, which is made of metal is in electrical contact with guide member 48 and that the latter is in electrical contact with metal tube 50.

Each terminal conductor member 40 has a split sleeve portion 54 in which the companion lamp terminal 36 has a sliding fit. Said sleeve 54 is fixed to a disk 56 provided with a plurality of apertures 58 therethrough (as shown in Fig. 3 and as indicated in Fig. '7). The disk 56 is fixed to a metal stem which is movable in the companion bore 62 of holder member 44 and which projects into a companion recess 64 provided in an adjustable member 6 5. A spring 68 engages disk 55 of the terminal conductor member 40 and has an end portion which is engaged by the member 06. Each member 66 has a screw-threaded portion which is in screw-threaded engagement with holder member 44 in an enlarged portion of the bore 62. Washers F2 are provided to furnish water-tight joints between members 66 and holder member 44. Bores or water passages 62 are in communication with each other through a cross duct or passage 4. The opposite ends of each water jacket tube 32 engage washers I6 and H respectively carried by holder members 42 and 44. Flexible tubings l8 and are connected to tubes 50 to provide for the circulation of water or other cooling fluid through the jacket tubes 32 of the lamps. It will be understood that either tube 78 or tube 80 may be the inlet and the other tube 18 or 80, as the case may be, may be the outlet for the cooling medium, and it will be noted that the cooling medium enters one of the tubes 59, passes through the jacket tube 32 of one of the lamps, then into on of the bores 62 of holder member 44, from said bore through the cross passage I4 into the other bore 62, from the latter through the jacket tube 32 of the other lamp, and then through the other tube 50 of holder member 42.

Jacket tubes 32 are clamped between the holder members 42 and 44, with the ends of said jacket tubes in fluid-tight engagement with said holder members respectively by reason of the provision of the washers or packings I6 and I7. Holder members 42 and 44 are held in assembled relation with the lamps by means of rods 82, there being preferably four such rods. Each rod is in the form of an elongated slender bolt, the head 84 of which is seated in a recess in section 86 of holder member 42. The threaded ends of said bolt rods 82 pass through companion openings, respectively, in holder member 44 and are engaged by companion nuts 88. Insulation sleeves are provided in the openings of holder member 44 through which rods 82 extend. It will be understood that when nuts 88 are tightened water jacket tubes 32 are in fluid-tight engagement with holder members 42 and 44.

The holder members 42 and 44 and the lamps held thereby are supported as a unit by the supporting or mounting means new to be described. Said mounting means comprises a member 92 formed of metal and having an inner cylindrical surface 94 which is engaged by the outer cylindrical surface of the lamp holder member 44. Member 92 is provided with a peripheral flange I00 which prevents movement of holder member 44 axially of member 92 in one direction. It will be understood that member 44 is rotatable in member 92 about the common axis of said two members. When, as here shown, the multiple lamp device is provided with two lamps, member 44 is turnable through an arc of so that either of said lamps may be brought into registry with lens I6 or light outlet I4 of the lamp housing in position nearer to said lens or light outlet than the other of said lamps. As shown in the drawings a spring-pressed pin I92 is provided on mounting member 92 in position to engage holder member 44 in either of two diametrically opposite indexing recesses I04 for releasably holding member 44 and the rest of the multiple lamp device in proper operative position in relation to the lens or light outlet of the lamp housing. Holder member 44 is provided with a pair of recesses I 06 in its outer surface to receive the ends of an appropriate tool which may be used for turning member 44 in mounting member 92. Preferably, as here shown stop pins I08 are provided on member 44 in position to engage a stop member IIO carried by mounting member 92 for limiting the extent of turning movement of member 44 whereby to prevent over-twisting of the flexible tubing 18 and 80.

Mounting member 92 is provided with an integral part or base H2 by which said mounting member is secured to the adjustable support or bracket II4, which is described in detail in my abovementioned application, but which will be briefly described herein. Said bracket H4 is pivotally mounted on a rod 6 and is also adjustable longitudinally of said rod for the purpose of moving the multiple lamp device in a direction transversely of the axis of the lamp tubes 30 and also in the direction of the length of said lamp tubes for properly aligning the lamps with the lens I6 and/or th light outlet I4. Rod 1 I6 has a threaded portion I I8 which is in screwthreaded engagement with the internally threaded split collar I20 of bracket H4, and said rod is mounted in a bearing bracket member I22 which is carried by the lamp housing, said rod being rotatable in said bracket but being held against longitudinal movement by the collar I24 and by the shoulder I26 which engage the opposite sides of bearing I28. Rod IIB may be rotated by the member I30 when the latter is disengaged from the lamp housing and inserted through the opening I32 of said housing for engaging the split end I34 of said operating member with the cross pin I36 of rod I I6, as described in my abovementioned application. Transverse movement of the multiple lamp device III, is effected by pivotal movement of supporting bracket II4 on rod H6, and for this purpose the upper part of said bracket has a knuckle member I38 pivotally connected thereto, and said knuckle member is pivotally connected to an internally threaded sleeve I40 which is engaged by the screw-threaded stem I42 which is mounted for rotation in the door I44 of the lamp housing. Stem I42 is held against movement longitudinally of itself so that when said stem is turned by the operating knob I46 sleeve I40 is moved in 2 the direction of its axis whereby to move bracket member II4.

In accordance with the present invention provision is made for automatically connecting one of the lamps in the electric circuit for operation of said lamp and for disconnecting the other lamp of said unit, when the lamp which is to be used is moved to its operative position by turning lamp holder member 44 in mounting member 92 as hereinbefore described. For this purpose lamp holder member 42 is provided with a plurality of electrical contact members I48, one for each lamp ,30. Each contact member is secured to acompanion metal tube 50 and is in goodelectrical contact therewith. Said contact members I48 are disposed within an annular space formed by the section 86 and the companion section I52 of lamp holder member 42, said sections being formed of insulating material. Said sections 86 and I52 define a peripheral groove I54 in which a ring I56 of insulating material is mounted for relative rotation. Sections 66 and I52 are held together in any suitable way as by screws I51. Ring I56 carries an electrical contact member I66, said contact member being connected to an electrical conductor terminal I62 mounted in an insulation sleeve I64. Said sleeve I64 is held against rotation by a member I66 which is secured to bracket I I4. Sleeve I64 is fixed to ring I56 so that said ring is held against turning movement. Accordingly it wil be understood that when member 44 is turned in mounting member 92 for bringing one of the lamps 30 into operating position, the contact member I48 of said lamp is electrically engaged with the contact member I60, while the contact member I48 of the other lamp is moved out of engagement with said contact member I60. It will be understood that contact member I60 is connected to one side of the electrical supply line, and that the other side of said line is connected to the lamps as indicated by the terminal wire I68 as illustrated in Fig. 4. As here shown wire I68 is electrically connected to the mounting member 92 which is in electrical contact with the holder member 44 which, as described above, is made of metal.

Various changes in the details of construction and in the form and arrangement of parts may be made without departing from the underlying ideas or principles of my invention within the scope of the appended claims.

Having thus described my invention, what I claim and desire to secure by Letters Patent is:

1. A multiple lamp unit, comprising a plurality of tubular electric lamps disposed in laterally spaced relation, each of said lamps having an individual tubular cooling jacket, means for holding said lamps in said relation, and mounting means for supporting said lamp-holding means for-turning movement about an axis parallel to the axes of said lamps, said lamp-holding means comprising spaced members between which said lamps and their cooling jackets extend, each of said lamps having terminals at its opposite ends and each of said spaced members being provided with terminal supports and conductors for each of said lamps, said spaced members engaging the opposite ends, respectively, of said cooling jackets and having fluid passages in communication with said jackets at said opposite ends thereof, and

means operable concomitantly with the movement'of said holding means in predetermined relation to said mounting means to effect connection of one of said lamps with a source of electric current and to disconnect another of said lamps from said source, said connect and disconnect means comprising contact members electrically connected to the terminal supports, respectively, of one of said spaced members and a contact member which is engaged by and disengaged from said contact members, respectively, in a predetermined position of said holding means in relation to said mounting means, said contact member extending into said one spaced member, and an annular member retained in fixed disposition and carrying said contact member, said one spaced member being mounted within said annular mem'. ber. for rotation relative thereto.

,2. A multiple lamp unit, comprising a plurality of tubular electric lamps disposed in laterally spaced relation, each of said lamps having a tubular jacketfor a cooling fluid, means for holding said lamps in said relation, and mounting means for supporting said lamp-holding means for turning movement about an axis parallel to the axis of said lamps, said lamp-holding means comprising spaced members between which said lamps and said cooling jackets extend, each of saidlamps having terminals at its opposite ends and each,of said spaced members being provided with terminal supports and conductors for each of said lamps, means carried by said spaced members forming fluid passages in communication with said jackets to provide for the circulation of cooling fluid through said jackets, one of said spaced members having one of said fluid passages connecting the adjacent ends of said jackets to each other, and the other of said spaced members having the fluid passages thereof connected individually to the other adjacent ends of said jackets, respectively, for the supply of the cooling fluid through one of said passages of said other spaced member and the exhaust of the cooling fluid from said lamps through another of said passages of said other spaced member, and means operable concomitantly with the movement of said holding means in predetermined relation to said mounting means to effect connection of one of said lamps with a source of electric current and to disconnect another of said lamps from said source, said concomitantly operable means including a member retained in spaced disposition relative to said mounting means and disposed coaxially thereof, one of said spaced members being rotatable within said mounting means and the other of said spaced members being rotatable concomitantly in said retained member.

3. A multiple lamp unit, comprising a plurality of tubular electric lamps disposed in laterally. spaced relation, means for holding said lamps in said relation, and mounting means for supporting said lamp-holding means for turning movement about an axis parallel to the axes of said lamps, said lamp-holding means comprising spaced members between which said lamps extend, each of said lamp having terminals at its opposite ends and each of said spaced members being provided with terminal supports and conductors for each of said lamps, and means operable concomitantly with the movement of said holding means in predetermined relation to said mounting means to effect connection of one of said lamps with a source of electric current and to disconnect another of said lamps from said source, said connect and disconnect means comprising contact members electrically connected to the terminal supports, respectively, of one of said spaced members in insulated relation therewith and a contact member which is engaged by and disengaged from said contact members, respectively, in a predetermined position of said holding means in relation to said mounting means, said last-mentioned contact member being stationary and said first-mentioned contact members being movable with said one of the spaced members of said lamp-holding means, said mounting means comprising an electrically conductive member and the other of said spaced members of said holding means being movably supported by and in electrically conductive relation tosaid conductive member of said mount-.

ing means, said Spaced holding members being insulated from each other but connected to each other for conjoint movement, said one of the spaced members being formed of insulating material and having both an annular chamber therein and a peripheral groove, said movable contact members extending into said chamber, and an insulating ring mounted in said groove for relative rotation, said stationary contact member being carried by said ring and extending into aid chamber for engagement and disengagement by said movable contact members upon said conjoint movement of said spaced holding members.

4. A multiple lamp unit, comprising a plurality of tubular electric lamps disposed in laterally spaced relation, means for holding said lamps in said relation, and mounting means for supporting said lamp-holding means for turning movement about an axis parallel to the axes of said lamps, said lamp-holding means comprising spaced members between which said lamps extend, each of said lamps having terminals at its opposite ends and each of said spaced members being provided with terminal supports and conductors for each or" said lamps, and means operable concomitantly with the movement of said holding means in predetermined relation to said mounting means to effect connection of one of said lamps with a source of electric current and to disconnect another of said lamps from said source, said connect and disconnect means comprising contact members electrically connected to the terminal supports, respectively, of one of said spaced members in insulated relation therewith and a contact member which is engaged by and disengaged from said contact members, respectively, in a predetermined position of said holding means in relation to said mounting means, said last-mentioned contact member being stationary and said first-mentioned contact members being movable with said one of the spaced members of said lamp-holding means, said mounting means comprising an electrically conductive member and the other of said spaced members of said holding means being movably supported by and in electrically conductive relation to said conductive member of said mounting means, said spaced holding members being insulated from each other but connected to each other for conjoint movement, said one of the spaced members being formed of insulating material and having both an annular chamber sage therein connecting the adjacent ends of said jackets to each other, and said one of said spaced members having fluid passages formed therein and connected individually to the other adjacent ends of said jackets.

5. A mounting unit for a plurality of electric tubular lamps of the type which are provided with terminals at their opposite ends, said unit comprising a first electrically conductive supporting member, a first insulation supporting member spaced laterally of said first mentioned supporting member, said two members having co-axial cylindrical bearing surfaces, a second electrically conductive member rotatably engaging said bearing surface of said first electrically conductive member, a second insulation member rotatably engaging said bearing surface of said first insulation supporting member, each or said second members having a plurality of laterally spaced lamp terminal members, one for each lamp, each terminal member in one of said second members being paired with a terminal member in the other of said second members to receive a lamp therebetween, the terminal members in each pair being co-axial, respectively, for engagement by the terminals at the opposite ends or a lamp, the terminal members on said second insulaticn member being insulated from each other, movable contact members carried by said second insulation member and electrically connected to the terminal members, respectively, of the latter, a relatively stationary contact member carried by said first insulation member and engageable by one only of said first mentioned contact members in a predetermined position of said second insulation member circumferentially of said first insulation member, and means connected to and extending between said second conductive member and said second insulation member for holding them together for conjoint rotary movement in engagement with said bearing surfaces, respectively, for engaging one of said movable contact members with said relatively stationary contact member and concomitantly disengaging another of said movable contact members therefrom.

6. A mounting unit as defined by claim 5, wherein the second conductive member and the second insulation member are provided with fluid passages disposed in co-axial alignment around said co-axial terminal members and open at the confronting sides of said second conductive and insulation members to register with the opposite open ends, respectively, of tubular cooling jackets for the lamps.

7. A multiple lamp device, comprising lampholding means, a plurality of electric lamps carried by said holding means, means on which said lamp-holding means is movably mounted for movement to different positions, said mounting means having a peripheral bearing surface, said lamp-holding means comprising spaced confronting members between which said lamps extend. one of said members having a rotary bearing on said surface, each of said lamps having terminals at its opposite ends and each of said spaced confronting members being provided with terminal supports and conductors for each of said lamps whereby said lamps are supported at their 0pposite ends, respectively, and are also electrically connected to said terminal supports, one of said spaced members having an electrical connection with said lamp-terminal supports thereof and the other of said spaced members holding said lamp-terminal supports thereof in insulated relation, and means operable by movement of said holding means in predetermined relation to said mounting means to effect connection of one of said lamps with a source of electric current and to disconnect another of said lamps from said source.

8. A multiple lamp device, comprising lampholding means, a plurality of electric lamps carried by said holding means, means on which said lamp-holding means is movably mounted for movement to difierent positions, said mounting means having a peripheral bearing surracc, said lamp-holding means comprising spaced confronting members between which said lamps extend, one of said members having a rotary bearing on said surface, each of said lamps having terminals at its opposite ends and each of said spaced confronting members being provided with terminal supports and conductors for each of said lamps whereby said lamps are supported at their opposite ends, respectively, and are also electrically connected to said terminal supports, one of said spaced members having an electrical connection with said lamp-terminal supports thereof and the other of said spaced members holding said lamp-terminal supports thereof in insulated relation, and means operable by movement of said holding means in predetermined relation to said mounting means to effect connection of one of said lamps with a source of electric current and to disconnect another of said lamps from said source, said connect and disconnect means comprising contact members carried by said other spaced member and connected to said terminal supports, respectively, thereof, and a companion stationary contact member carried by said device and with respect to which said first-mentioned contact members are movable for engagement with and disengagement from said companion contact member automatically in different predetermined positions of said holding means in relation to said mounting means.

9. A multiple lamp device, comprising lampholding means, a plurality of electric lamps carried by said holding means, means on which said lamp-holding means is movably mounted for movement to different positions, said mounting means having a peripheral bearing surface, said lamp-holding means comprising spaced confronting members between which said lamps extend, one of said members having a rotary bearing on said surface, each of said lamps having terminals at its opposite ends and each of said spaced confronting members being provided with terminal supports and conductors for each of said lamps whereby said lamps are supported at their opposite ends, respectively, and are also electrically connected to said terminal supports, one of said spaced members having an electrical connection with said lamp-terminal supports thereof and the other of said spaced members holding said lamp-terminal supports thereof in insulated relation, and means operable by movement of said holding means in predetermined relation to said mounting means to effect connection of one of said lamps with a source of electric current and to disconnect another of said lamps from said source, said connect and disconnect means comprising contact members carried by said other spaced member and connected to said terminal supports, respectively, thereof, and a companion stationary contact member carried by said device and with respect to which said first-mentioned contact members are movable for engagement with and disengagement from said companion contact member automatically in different predetermined positions of said holding means in relation to said mounting means, said mounting means including a stationary insulating member on which said companion contact member is mounted, said insulating member having an inner surface through which said stationary contact member extends into said other of said spaced holding members, and said latter one of said spaced holding members having a rotary bearing in said insulating member.

10. A multiple lamp unit, comprising lampholding means, a plurality of tubular electric lamps carried by said holding means, each of said lamps having an individual tubular jacket for a cooling fluid, means on which said lampholding means is movably mounted for movement to different positions, said mounting means being free of fluid passages therein, said lamp-holding means comprising spaced confronting members between Which said lamps extend, said spaced confronting members engaging and supporting the opposite ends, respectively, of said cooling jackets and having fluid passages in communication with said jackets at said opposite ends thereof, fluid-intake and fluid-outlet means being provided on said holding means for said fluid passages, each of said lamps having terminals at its opposite ends and each of said spaced confronting members being provided with terminal supports and conductors for each of said lamps whereby said lamps are supported at their opposite ends, respectively, and are also electrically connected to said terminal supports, and means operable by movement of said holding means in predetermined relation to said mounting means to effect connection of one of said lamps with a source of electric current and to disconnect another of said lamps from said source.

11. A multiple lamp unit, comprising a plurality of tubular electric lamps disposed in laterally spaced relation, each of said lamps having a tubular jacket for a cooling fluid, means for holding said lamps in said relation, and mounting means for supporting said lamp-holding means for turning movement about an axis parallel to the axis of said lamps, said lamp-holding means comprising spaced members be'ween which said lamps and said cooling jackets extend, each of said lamps having termina s at its opposite ends and each of said spaced members being provided with terminal supports and conductors for each of said lamps, said spaced members being provided with fluid passages in communication with said jackets to provide for the circulation of cooling fluid through said jackets, one of said spaced members having one of said fluid passages connecting the adjacent ends of said jackets to each other, and the other of said spaced members having the fluid passages thereof connected individually to the other adjacent ends of said jackets, respectively, for the supply of the cooling fluid through one of said passages of said other spaced member and the exhaust of the cooling fluid from said lamps through another of said passages of said other spaced member, fluid-intake and fluid-outlet connections for said lamp unit being provided on said other spaced member in communica ion with said one passage and said othe passage, respectively, thereof whereby said mounting means is free of fluid-passage therethrough, and means operable concomitantly with the movement of said holding means in predetermined relation to said mounting means to effect connec ion of one of said lamps with a source of electric current and to disconnect another of said lamps from said source.

12. A multiple lamp unit comprising a plurality of tubular electric lamps disposed in laterally spaced relation, lamp-holding means comprising spaced members between which said lamps exend, each of said lamps having terminals at its opposite ends and each of said spaced members being provided with. terminal supports and conductors for each lamp, electrically conductive mounting means on which said lamp-holding means is movably mounted for movement to difierent positions, said mounting means having a peripheral bearing surface, one of said spaced members being electrically conductive and having a rotary bearing on said bearing surface, the other of said spaced members being free of engagement with said mounting means, and means operable concomitantly with the movement of said holding means in predetermined relation to said mounting means to effect connection of one of said lamps with a source of electric current and to disconnect another of said lamps from said source, said connect and disconnect means comprising contact members electrically connected to the terminal supports, respectively, of said other of said spaced members and a contact member carried by said unit and disposed to be engaged by and disengaged from said contact members, respectively, in a predetermined position of said holding means in relation to said mounting means.

13. A multiple lamp unit comprising a plurality of tubular electric lamps disposed in laterally spaced relation, lamp-holding mean comprising spaced members between which said lamps extend, each of said lamps having terminals at its opposite ends and each of said spaced members being provided with terminal supports and conductors for each lamp, electrically conductive mounting means on which said lamp-holding means is movably mounted for movement to different positions, said mounting means having a peripheral bearing surface, one of said spaced members being electrically conductive and having a rotary bearing on said bearing surface, the other of said spaced members being free of engagement with said mountin means, and means operable concomitantly with the movement of said holding means in predeermined relation to said mounting means to effect connection of one of said lamps with a source of electric current and to disconnect another or" said lamps from said source, said connect and disconnect means comprising contact members electrically connected to the terminal supports, respectively, of said other of said spaced members and a contact member disposed to be engaged by and disengaged from said contact members, respectively,

in a predetermined position of said holding means in relation to said mounting. means, said other of said spaced members being non-conductive, and a non-conduc ive support for said latter member, said contact member being carried by said non-conductive support.

14. A multiple lamp unit comprising a plurality of electric lamps disposed in laterally spaced relation, lamp-holding means comprising spaced members between which said lamps extend, each of said lamps having terminals at its opposite ends and each of said spaced members being provided with terminal supports and conductor: for each lamp, electrically conductive mounting means on which said lamp-holding means is movably mounted for movement to different positions, said mounting means having a peripheral bearing surface, one of said spaced members being electrically conductive and having a rotary bearing on said bearing surface, the other of said spaced members being free of engagement with said mounting means, and means operable concomitantly with the movement of said holding means in predetermined relation to said mounting means to efiect connection of one of said lamps with a source of electric current and to disconnect another of said lamps from said source, said connect and disconnect means comprising contact members electrically connected to the terminal supports, respectively, of said other of said spaced members and a contact member carried by said unit and disposed to be engaged by and disengaged from said contact members, respectively, in a predetermined position of said holding means in relation to said mounting means, each of said lamps having a jacket for a cooling fluid, said spaced members engaging and supporting the opposite ends, respectively, of said jackets, means carried by said spaced members forming fluid passages in communication with said jackets to provide for the CiICUIaLiOD of cooling fluid through said jackets, said one spaced member having one of said fluid passages connecting the adjacent ends of said jackets to each other, said other of said spaced members having the fluid passages thereof connected individually to the other adjacent ends of said jackets, respectively, for the supply of the cooling fluid through one of said passages of said other spaced member and the exhaust of the cooling fluid from said lamps through another of said passages of said other spaced member, fluid-intake and fluid-outlet means for said lamp unit being provided on said other spaced member in communication with said one passage and said other passage, respectively, thereof whereby said mounjng means is free of fluidpassage therethrough.

EDWIN- C. WEISKOPF.

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